Warn if pushed options require DHCP

Some pushed options (such as DOMAIN-SEARCH) require DHCP server to work. Warn user that some options will not work if the current driver (such as dco-win) doesn't support DHCP. While on it, indicate that "--dns search-domains" option requires DHCP. Change-Id: Ie512544329a91fae15409cb18f29d8be617051a1 Signed-off-by: Lev Stipakov <[email protected]>
lstipakov · Nov 10, 2023 · c69924a · c69924a
1 parent 552d140
commit c69924a
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Showing 2 changed files with 9 additions and 2 deletions.
diff --git a/src/openvpn/options.c b/src/openvpn/options.c
@@ -2483,10 +2483,10 @@ options_postprocess_verify_ce(const struct options *options,
 
     if (options->tuntap_options.dhcp_options & DHCP_OPTIONS_DHCP_REQUIRED)
     {
-        const char *prefix = "Some dhcp-options require DHCP server";
+        const char *prefix = "Some dhcp-options (or --dns) require DHCP server";
         if (options->windows_driver != WINDOWS_DRIVER_TAP_WINDOWS6)
         {
-            msg(M_USAGE, "%s, which is not supported by selected %s driver",
+            msg(M_USAGE, "%s, which is not supported by the selected %s driver",
                 prefix, print_windows_driver(options->windows_driver));
         }
         else if (options->tuntap_options.ip_win32_type != IPW32_SET_DHCP_MASQ

diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
@@ -6826,6 +6826,13 @@ void
 open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt,
          openvpn_net_ctx_t *ctx)
 {
+    if ((tt->options.dhcp_options & DHCP_OPTIONS_DHCP_REQUIRED)
+        && tt->windows_driver != WINDOWS_DRIVER_TAP_WINDOWS6)
+    {
+        msg(M_WARN, "Some dhcp-options or --dns require DHCP server, which is not supported by the selected %s driver. Expect them not to work.",
+            print_windows_driver(tt->windows_driver));
+    }
+
     /* dco-win already opened the device, which handle we treat as socket */
     if (tuntap_is_dco_win(tt))
     {